1. Field of the Invention
The present invention generally relates to an apparatus that control an intake quantity of a supercharged engine. More specifically, the present invention relates to an engine intake quantity control apparatus that controls output torque of a supercharged engine.
2. Background Information
One example of an engine intake quantity control apparatus is disclosed in Japanese Laid-Open Patent Publication No. 2005-76498. This publication discloses an engine intake quantity control apparatus that controls an intake air quantity supplied to a supercharged engine by combining a throttle control and a supercharge pressure control. The throttle control is configured to control an intake air quantity by adjusting an opening degree of a throttle valve. The supercharge pressure control is configured to control an intake air quantity by adjusting a supercharge pressure produced by a supercharger.
Sometimes when a vehicle moves from a flat road to an inclined road, the engine rotational speed will not increase and, instead, remains constant even though the driver is depressing the accelerator pedal. When the engine rotational speed is constant and the opening degree of the throttle valve has reached a saturation throttle valve opening degree, the intake air quantity will not increase even if the throttle valve opening degree is increased. In view of this issue, the intake quantity control apparatus presented in the aforementioned publication is configured to switch from using the throttle control to control the intake air quantity to using the supercharge pressure control to control the intake air quantity when the throttle valve opening degree has exceeded the threshold throttle valve opening degree.